Bees work on their hive on the rooftop of the Tour d'Argent restaurant in Paris, France. Jacky Naegelen/Reuters/File

Bee inspector Neil Trent of Scientific Ag Co. inspects a frame of bees to assess the colony strength Feb. 12, 2013, near Turlock, Calif. Some bee hives in the state have weak colonies of bees, spelling a bee shortage for almond bloom, Trent says. Gosia Wozniacka/AP

Honeybees cluster on top of the frames of an opened hive in an almond orchard Feb. 12, 2013, near Turlock, Calif. Bee brokers, beekeepers, and almond growers across the state say there is a shortage of healthy bees for this year’s almond pollination, which starts in mid-February. Gosia Wozniacka/AP

Scavenger bees look for nourishment over a dead hive at a bee farm east of Merced, Calif., in March 2010. The mysterious 4-year-old crisis of disappearing honeybees is deepening. Two federal agencies along with regulators in California and Canada are scrambling to figure out what is behind this relatively recent threat, ordering new research on pesticides already in use. Marcio Jose Sanchez/AP/File

Bees pollinate almond trees at an orchard near Bakersfield, Calif. In 2011, for the first time ever, the value of the California almond crop surpassed the state's iconic grape industry to move into second place, behind dairy. Almond-producing land is among the highest-priced and most sought-after acreage in the region. Gosia Wozniacka/AP

Charlotte Chan (l.) and Debbie O'Dowd from the Friends of the Earth environmental group pose for photographs in a temporary wildflower meadow by the River Thames, London, in April 2012. The publicity event was held to raise awareness of the group's claims that Britain has lost honey bees as a result of loss of their natural habitat and intensive farming. Matt Dunham/AP

A corn pesticide manufactured by the German chemical company Bayer has come under scrutiny in two scientific studies that indicate that it is responsible for mass deaths of pollinating bees.

ByJosephine Marcott, Minneapolis Star TribuneApril 6, 2012

Michael Reilly/Daily News-Record/AP

In a spring ritual as old as life itself, Steve Ellis' bees return to their hives day after day loaded with pollen from the dandelions and flowering trees that are in full bloom across central Minnesota.